1. Field of Invention.
This invention relates generally to devices and methods for producing holes in metal piping. More specifically, this invention relates to devices and methods for safely producing holes in gasoline tank fill pipes.
2. Related Art.
Large underground fuel tanks, such as those used at gasoline filling stations, typically have a metal tank fill pipe extending from ground level to a top end of the tank. Generally, the fuel tanks contain both fuel and water.
Operators utilize a variety of sensors to keep track of certain key characteristics of the tank and its contents. Such characteristics may include the level of the fuel, the level of the water, and the temperature of the tank. Many of these sensors are electronic, transmitting their signal to an instrumentation housing and then to a display device.
Presently, the majority of the sensors and the electrical wiring required to transmit the information to the sensor display device are installed through an unused bung on the top of the tank. Installation of a sensor in an unused bung requires a disinterring of the tank and subsequent repair of the surface. Disinterring the tank is both expensive and disruptive.
A second method of mounting the sensor and associated electrical wiring is to install the sensor through the tank fill pipe. In order to install the sensor through the fill pipe, a hole must normally first be made through the fill pipe. Because the installation of a sensor is usually performed after the gasoline tank is in use, the hole is normally made through the fill pipe with the tank already holding gasoline. Therefore, great care must be taken when making the hole to avoid creation of a spark which could ignite the gasoline in the tank.
Unfortunately, it is common for people in the field to use electric drills to create the hole through the fill pipe. The use of an electric drill causes friction which can create a spark or raise the temperature in the tank. Such a process poses great danger to people and property as it could result in igniting the gasoline in the tank.
It would thus be a great benefit to invent an apparatus or method which creates a hole in the fill pipe of an at least partially filled gasoline tank without generating friction.